1. Field of the Invention
The present invention relates to a device for butt splicing webs such as plastic films, paper, metal foil or the like and, in particular, to such web butt splicing device in which the following end of a first roll of web is butt spliced to the leading end of a second roll of web and thereby the webs can be supplied successively to a following treatment line.
2. Description of the Related Art
Conventionally, an operation to butt splice the following end of a first roll of web, which has been rewound completely, to the leading end of a second roll of web to be rewound has been performed manually by an operator. In other words, when the rewinding of the first roll of web gets near completion, then the following end portion of the first roll of web is cut on a butt splicing table arranged in a carrier line. Next, the leading end of the second roll of web is moved and guided to the butt splicing table by the operator, is positioned on the butt splicing table, and is then butt spliced to the following end of the first roll of web. After then, the operator splices the butt spliced ends by use of a splicing tape.
Besides the manual web butt splicing method mentioned above, a web butt splicing device set forth in Japanese Patent Publication No. 48-38461 discloses a cutting method in which a web cutting drum is combined with a web cutting/splicing drum. Also, web butt splicing device set forth in Japanese Patent Application laid-open (Kokai) No. 59-24526 discloses a device for automatically guiding the leading end of a second roll of web to the splice position thereof thereof by means of a holding device.
However, in the above-mentioned web butt splicing method using the manual operation by the operator, there are found drawbacks as follows. At first, in the web splicing operation, other portions of the web than the web portion existing on the butt splicing table are treated in a continuous way by operating an accumulator such as a reservoir or the like without stopping a treatment line, but, if the splicing operation by the operator drags on, then the amount of accumulation may exceed its limit, which causes the line to stop. Secondly, the manual splicing operation places the operator under restraint and thus, if the splicing operation is carried out very frequently, then the operating efficiency thereof is lowered. Another problem is that such web butt splicing operation is not always safe.
Also, in the web butt splicing device in Japanese Patent Publication No. 48-38461, due to the fact that the carrying speed of the second roll of web is different from the carrying speed of the first roll of web, the positioning of the webs cannot be executed accurately. Further, in the web butt splicing device in Japanese Patent Application laid-open (Kokai) No. 59-24526, if the webs to be treated are too flexible, then it is impossible to position the leading end of the second roll of web on the web butt splicing table with accuracy.